A reason is that if you accept them, you have to start to work some kind of equivalencies for the RPM
: a rotary engine gives you three (or four, or whatever) "strokes" per revolution. I think you'll need some rule like "no more than x power strokes per revolution" and "not more than y volumetric displacement per revolution", which would complicate things a bit.Mazda R26B: ain't a beauty?
As Belatti says, rotary engines would also require (or be burdened if they don't have) rules to equalize fuel consumption
, as they are famous for bad fuel economy, which goes against the "green" thing. I'm not aware of recent advances in that field, probably they have had them at Mazda, I don't know if someone can help us here.
Rotary engines have a poor reputation for torque
, altough some people argues the opposite. Again, I'm not aware of recent advances about that and I'm not sure about that issue: I haven's seen actual data.
As BJH_F1 clearly states, you cannot be totally sure about their reliability
(the RX-7 guys will jump at that, I think). Anyway, once they're heated they work pretty well, but heat cycles impact them more than piston driven engines. I just repeated that argument to say that the rings on a regular piston are wonderful devices that sometimes makes you forget about "heat driven" tolerances in an engine.
Also, manufacturers have used more or less "exotic" materials
to build them for regular cars, including (in times of yore) ceramic: that's another issue, as materials are restricted.
is wonderful for many people, that's a plus.
They were accepted but not used, as far as I know, in Formula 3. The 2002 rules stated:
Cars with rotary piston engines covered by NSU-Wankel patents will be admitted on the basis of a piston displacement equivalence. This equivalence is 1.5 the volume determined by the difference between the maximum and minimum capacity of the working chamber.
They, again in my knowledge, contaminate quite a bit and are thirsty for oil.
Finally, no manufacturer in F1 produces them, and, under the current efforts to restrict costs, I wonder who will wish to spend the development money.
My conclusion is that, unless Mazda enters F1, you will never see them racing there.